Water infrared analysis

Reaction of K3Co(CN) with PMMA. A 1.0 g sample of PMMA and 1.0g of the cobalt compound were combined in a standard vessel and pyrolyzed for 2 hrs at 375°C. The tube was removed from the oven and the contents of the tube were observed to be solid (PMMA is liquid at this temperature). The tube was reattached to the vacuum line via the break-seal and opened. Gases were determined by pressure-volume-temperature measurements on the vacuum line and identified by infrared spectroscopy. Recovered were 0.22g of methyl methacrylate and 0.11 g of CO and C02. The tube was then removed from the vacuum line and acetone was added. Filtration gave two fractions, 1.27g of acetone insoluble material and 0.30g of acetone soluble (some soluble material is always lost in the recovery process). The acetone insoluble fraction was then slurried with water, 0.11 g of material was insoluble in water. Infrared analysis of this insoluble material show both C-H and C-0 vibrations and are classified as char based upon infrared spectroscopy. Reactions were also performed at lower temperature, even at 260°C some char is evident in the insoluble fraction. 

The external reflection of infrared radiation can be used to characterize the thickness and orientation of adsorbates on metal surfaces. Buontempo and Rice [153-155] have recently extended this technique to molecules at dielectric surfaces, including Langmuir monolayers at the air-water interface. Analysis of the dichroic ratio, the ratio of reflectivity parallel to the plane of incidence (p-polarization) to that perpendicular to it (.r-polarization) allows evaluation of the molecular orientation in terms of a tilt angle and rotation around the backbone [153]. An example of the p-polarized reflection spectrum for stearyl alcohol is shown in Fig. IV-13. Unfortunately, quantitative analysis of the experimental measurements of the antisymmetric CH2 stretch for heneicosanol [153,155] stearly alcohol [154] and tetracosanoic [156] monolayers is made difflcult by the scatter in the IR peak heights. 

Table 4 lists the specifications set by Du Pont, the largest U.S. producer of DMF (4). Water in DMF is deterrnined either by Kad Fischer titration or by gas chromatography. The chromatographic method is more rehable at lower levels of water (<500 ppm) (4). DMF purity is deterrnined by gc. For specialized laboratory appHcations, conductivity measurements have been used as an indication of purity (27). DMF in water can be measured by refractive index, hydrolysis to DMA followed by titration of the Hberated amine, or, most conveniendy, by infrared analysis. A band at 1087 cm is used for the ir analysis. 

The deterrnination of impurities in the hehum-group gases is also accompHshed by physical analytical methods and by conventional techniques for measuring the impurity in question (93), eg, galvanic sensors for oxygen, nondispersive infrared analysis for carbon dioxide, and electrolytic hygrometers for water. 

Name two separate problems that occur when a sample for infrared analysis is contaminated with water. 

Two grams of HSPAN was added to 500 ml of water, the pH was adjusted from 9 to 6.5 with dilute hydrochloric acid, and 0.1 ml of Thermamyl 60L enzyme solution (Novo Enzyme Corp.) was added. The resulting mixture was heated at 95°C for 21 hr, and the clear yellow solution was exhaustively dialyzed against distilled water. Freeze drying yielded 1.235 g of polymer, which contained only about 5% residual carbohydrate (by infrared analysis). The number average molecular weight of this polymer was 44,000, as determined in 0.15N sodium chloride solution on a Melabs Model CSM-2 membrane osmometer equipped with a B-19 membrane (Schleicher and Schuell Co.). 

Just about the same time Japanese workers (107) polymerized this dialdehyde with boron trifluoride etherate, p-toluene sulfonic acid, and titanium tetrachloride as well as with aluminum triethyl-water catalyst systems. Completely insoluble products were obtained with the cationic catalysts, whereas partially soluble materials were isolated with the latter initiator. On the basis of infrared evidence, the above structure was assigned to the soluble product. In spite of the fact that ether linkages were found by infrared analysis in the cationic product, the authors concluded that its structure was different from that of the soluble polymer obtained with organometallic catalyst. The structure of the soluble fraction was assumed to be ... 

Treatment with fuming sulfuric acid produces an irreversible change in BBB but has no effect on BBL if the polymer is cyclized completely to give the structure indicated above. Further condensation may occur in solution in fuming sulfuric acid if the BBL is not formed completely before dissolution. Infrared analysis of the acid-treated BBB after precipitation in water shows the presence of sulfone and sulfonate groups, and gravimetric analysis shows that the polymer contains one sulfur... 

Samples used for infrared analysis must be free from water because it absorbs so much radiation itself that it obliterates much information from other groups that might be present. Therefore samples of a material are dried and usually mixed with Nujol oil, or compressed with potassium bromide powder and put under great... 

The liquid reaction mixture was extracted with CC14. Infrared analysis of the extract did not indicate any additional products. The aqueous residue was evaporated to dryness at room temperature, and a few needle crystals were recovered. The infrared spectrum of this solid showed only absorptions owing to water. Attempts to dehydrate the small amount of product which remained were unsuccessful. 

The infrared identification method was used for 19 fish samples containing 12 chlorinated insecticides, alone or in combination. Two samples were collected at the site of a large fish-kill two others were controls from a reputedly uncontaminated source. A total of 14 samples consisted of fish exposed to insecticides in the water of an aquarium at a constant concentration (p.p.b. level) or dosed by oral ingestion once daily (p.p.m. level). Muscle tissue and viscera of the various fish samples were processed separately. The last sample was a can of California mackerel, packed in water and purchased at a local market (to serve as an example of marine fish). This sample contained both DDE and DDD DDE was identified by infrared analysis in the small amount of oil separated in the container. 

There are several laboratory tests available for identifying the type of contaminant and its concentration. If onsite laboratory facilities are not available, these tests can be conducted by an independent laboratory or a water-treatment consultant. Tests include gravimetric analysis, infrared analysis, spot testing, chromatography and measurement of total organic carbon (TOC). 

Transition metal carbonyl clusters intercalated with lamellar materials such as graphite or smectites have been prepared and have been shown to be useful in catalysis 68). For instance, sodium montmorillonite was impregnated with [Ru(NH3)5]Cl3 in water under reflux. After flltration and drying, the resulting complex was dissolved in methanol and reduced with carbon monoxide at 80°C, 100 bar, for 16 hours. Infrared analysis has shown the formation of a sodium montmorillonite-intercalated [Ru3(CO),2] complex. This system was claimed to be active for the hydro-formylation of propene either with CO/Hj or CO/HjO in the presence of a basic promoter. 

Near-Infrared Spectroscopy. Near-infrared (NIR) spectroscopy is a technique that has been around for some time but, like NMR spectroscopy, has only recently been improved and developed for on-line applications. Near-infrared analysis (NIRA) is a nondestructive technique that is versatile in the sense that it allows many constituents to be analyzed simultaneously 112, 113). The NIR spectrum of a sample depends upon the anharmonic bond vibrations of the constituent molecules. This condition means that the temperature, moisture content, bonding changes, and concentrations of various components in the sample can be determined simultaneously. In addition, scattering by particles such as sand and clay in the sample also allows (in principle) the determination of particle size distributions by NIRA. Such analyses can be used to determine the size of droplets in oil-water emulsions. 

Infrared analysis of water associated with a solid centers on an assessment of the degree to which the... 

In this paper, instrumental means are used to obtain a physical description of the rise of urethane foam and cell opening. Infrared analysis is used to identify the chemical species present in reacting foam and to determine the order and relative rates of reaction of these species. From these data, a reaction sequence model is deduced for the process of making stable, water-blown urethane foam. 

The infrared analysis was performed using samples cured between silver chloride plates. Conditioning of the resin was achieved by immersion in water. High temperature scans were made using a temperature regulated sample cell. Spectra were obtained with a Perkin-Elmer 283 spectrophotometer. 

ASTM Method D-3414-75T, Method for Infrared Analysis of Water-... 

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